to the coast at Herdísarvík bay forming lava falls on their way. Previously it was thought that this lava flow had ceased before the settlement of Iceland (i.e. the end of the 8th century), but this is now thought that this was not the case as the coastal trail (now Route 42) was covered in lava at one stage. The last eruption in the Brennisteinsfjöll volcanic system was a VEI-2 eruption in 1341. It is a possible cause of St. Mary Magdalene’s flood 1342 in Central Europe und following bad years with Black Death to 1350. Brennisstein is the word for sulfur on Iceland, so great sulfur emissions with worldwide cooling for some years are possible and quite normal by this volcanic system. Most of its rocks consist of basalt. Brennisteinsfjöll geothermal areas There is a high temperature geothermal area in Brennisteinsfjöll, but it is rather remote, about southeast of Reykjavík in the inner part of the Reykjavík peninsula. Fumaroles are to be found within an area of a few acres, and two more areas show signs of hydrothermal alteration. The surface conditions are complicated with a rough lava surface and the geothermal features which are located at a height of can only be reached on foot. The stratigraphy of the region includes hyaloclastite, older and younger lava flows. In a fault, not far from Grindarskörð , there are traces of a former geothermal area which is no more active. Sulfur mining As the name (Brennisteinsfjöll = Sulfur Mountains) suggests, sulfur is found here, though today in small amounts. But in the 19th century, a sulfur mine was run in the region by people from the United Kingdom. Mining was carried out just til the 1880s. The mine was situated in a lava slope. The sulfur “was deposited into holes and fractures in the lava and between lava layers”. It was therefore difficult to reach and mine. The miners had first to break up the lava to get to the sulfur. The current geothermal activity is above this area. The place of the former mine can be found by hiking the old trail Selvogsgata and the following the so-called Draugahlíðar between the lava and the slope. There are still some ruins of the former mine and traces of transportation paths. Known mountains, craters and other volcanic landforms Part of the Brennisteinsfjöll volcanic system are the Brennisteinsfjöll themselves (up on Hellisheiði),